Histological, Enzyme Histochemical, and Electron Microscopic studies of the Rat Kidney Following Administration of Folic Acid

ABSTRACT

To investigate the morphologic evidence of acute renal failure by folate, histological, histochemical (PAS), enzyme histochemical (Na-K-ATPase, G6PD, and ALP), and ultrastructural studies were performed. The results are as follows l) Oliguria was most severe 3 hours after folate and the urine volume was 24.8% that of the control group. 2) Histologically, dilatation of tubules, degeneration and focal necrosis of the cortical tubules, and PAS(+) droplets in the tubular lumen were noted. And also frequent mitoses, mild interstital connective tissue proliferation, and neutrophilic infiltrates were observed in the late stage. 3) On enzyme histochemical examination, the activities of Na-K-ATPase and ALP were decreased, but G6PD activity was increased in comparison with the control group. 4) The ultrastructural studies revealed cytoplasmic vacuoles, apical cytoplasmic blebbing, dense bodies, mildly swollen mitochondria, dilated endoplasmic reticulum, loss bf brush border of the proximal tubules, and loss of microvilli of the thin limb of Henle's loop. Later, marked attenuation or loss of infoldings of basal plasma membrane of the cortical tubules was recognized. According to above results, the cause of acute renal failure by late is thought to be the injuries of tubular epithelial cells including sodium pump secondary to tubular obstruction.